摘要
本文研究了用平均加速度的Newmark积分格式求解一维平面弹性波动问题的精度。由于平均加速度的Newmark积分格式没有振幅衰减、不产生数值阻尼,因此采用此法分析波动问题会产生较强的“高频振荡”,尤其是加速度的计算值误差甚大。本文对防护工程中常见的平台型荷载和升压三角形荷载作用下的波动问题,应用有限元分析的实例表明:采用有数值阻尼的Newmark积分格式是改进有限元求解波动问题的一个有效方法,可以大大地提高应力和加速度求解精度。文中推荐的有数值阻尼Newmark积分格式的积分参数(δ=0.9,β=0.49)可供工程中土与结构动力分析时参考使用。
This paper studies the accuracy of using the average acceleration method of New-mark's integral net in solving one-dimensional elastic wave propagation problems. Because the average acceleration method has no capabilities of amplitude decay and numerical damping,the strong oscillatory response may be resulted when using this method to analyse wave propagation problems,especially large error may be introduced in computational acceleration. In addition,this paper studies the elastic wave propagation problems under step loading and triangular loading, both with rise times, using numerical damping techniques. Numerical examples show that this technique is an effective way to improve the accuracy of FE analysis for wave propagation problems, greatly increasing the accuracy of computational stress and acceleration. Newmark method with the filtering property of parameter values <5=0. 9,β=0. 49 is suggested to be used in complicated soil-structure interaction analysis.
出处
《爆炸与冲击》
EI
CAS
CSCD
北大核心
1992年第1期45-53,共9页
Explosion and Shock Waves
关键词
有限元法
应力波
NEWMARK法
finite element method ,stress wave,Newmark method,numerical damping
